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59 lines
1.3 KiB
59 lines
1.3 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Delay loops based on the OpenRISC implementation. |
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* |
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* Copyright (C) 2012 ARM Limited |
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* |
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* Author: Will Deacon <[email protected]> |
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*/ |
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#include <linux/delay.h> |
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/timex.h> |
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#include <clocksource/arm_arch_timer.h> |
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#define USECS_TO_CYCLES(time_usecs) \ |
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xloops_to_cycles((time_usecs) * 0x10C7UL) |
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static inline unsigned long xloops_to_cycles(unsigned long xloops) |
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{ |
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return (xloops * loops_per_jiffy * HZ) >> 32; |
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} |
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void __delay(unsigned long cycles) |
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{ |
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cycles_t start = get_cycles(); |
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if (arch_timer_evtstrm_available()) { |
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const cycles_t timer_evt_period = |
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USECS_TO_CYCLES(ARCH_TIMER_EVT_STREAM_PERIOD_US); |
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while ((get_cycles() - start + timer_evt_period) < cycles) |
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wfe(); |
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} |
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while ((get_cycles() - start) < cycles) |
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cpu_relax(); |
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} |
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EXPORT_SYMBOL(__delay); |
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inline void __const_udelay(unsigned long xloops) |
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{ |
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__delay(xloops_to_cycles(xloops)); |
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} |
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EXPORT_SYMBOL(__const_udelay); |
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void __udelay(unsigned long usecs) |
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{ |
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__const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */ |
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} |
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EXPORT_SYMBOL(__udelay); |
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void __ndelay(unsigned long nsecs) |
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{ |
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__const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */ |
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} |
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EXPORT_SYMBOL(__ndelay);
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